问Api 21循环显示动画不起作用

EN

TmdbHelper helper = new TmdbHelper();
                helper.getMovieById(id, "en", new TmdbHelper.ResultListener() {
                    @Override
                    public void onResultReceived(JSONObject result) {

                        // called when finished downloading

                        try {
                            String rating = result.getString("vote_average");

                            AnimationHelper.circularReveal(fab, 500, 0); 

                            fab.setText(rating);

                        } catch (JSONException e) {
                            e.printStackTrace();
                        }

                    }
                });

    public static void circularReveal(final View view, final long duration, long startDelay) {

    // get the center for the clipping circle
    int cx = (view.getLeft() + view.getRight()) / 2;
    int cy = (view.getTop() + view.getBottom()) / 2;

    // get the final radius for the clipping circle
    int finalRadius = Math.max(view.getWidth(), view.getHeight());

    // create the animator for this view (the start radius is zero)
    Animator anim =
            ViewAnimationUtils.createCircularReveal(view, cx, cy, 0, finalRadius);

    anim.setDuration(duration);
    anim.setStartDelay(startDelay);

    anim.addListener(new Animator.AnimatorListener() {
        @Override
        public void onAnimationStart(Animator animation) {

            view.setVisibility(View.VISIBLE);
        }

        @Override
        public void onAnimationEnd(Animator animation) {
        }

        @Override
        public void onAnimationCancel(Animator animation) {
        }

        @Override
        public void onAnimationRepeat(Animator animation) {}
    });

    // make the view visible and start the animation

    anim.start();
}

headerContainer.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {

                @Override
                public void onGlobalLayout() {
                    headerContainer.getViewTreeObserver().removeOnGlobalLayoutListener(this);
                    AnimationHelper.circularReveal(headerContainer, 500, 200);
                }
            });